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cygus
Administrator
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Posted: Wed May 6th, 2009 10:01 pm |
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Space solar power might be the only way to fill the looming gap between growing demand for energy and limited supplies in the next century. (credit: © Mafic Studios Inc.)
Given strongly held personal and organizational preferences for space science, suborbital commercial human spaceflight, the human exploration of Mars, etc., it’s not surprising that achieving a consensus to support and strongly advocate for starting the commercial development of SSP has not yet been reached.
The SSP concept involves building extremely large space platforms, usually located in geostationary orbit (GEO), to convert sunlight into electrical energy and then transmit this energy to very large ground receivers where the energy is fed into electric utility grids.
Interest in SSP has reemerged in response to the public’s growing appreciation of the need to develop new sustainable energy sources. Compared to other terrestrial renewable alternatives, GEO SSP has four important advantages:
- Its scale of potential generation capacity is very large, an important consideration in formulating policies and plans to avoid future energy scarcity.
- It should have the ability to provide high quality electrical power—nearly 365 days of the year, 24 hours a day—for baseload electrical power supply comparable to nuclear energy.
- It should have nearly worldwide access and usability enabling countries to achieve a degree of energy independence even when traditional renewable energy sources are not practical.
- It should have important terrestrial environmental benefits, including avoiding thermal waste heat ejection and minimizing the land area otherwise needed for terrestrial renewable energy generation.
By 2100 and due entirely to population growth, the United States will require about 1.6X more energy than we are using today. With a population of about 307 million, the United States today uses about 17 billion barrels of oil equivalent (BOE) of energy annually from all sources—with roughly 85 percent coming from non-sustainable easy energy (oil, coal, and natural gas). By 2100, with a projected population of 560 million, the United States will require about 28 billion BOE annually even with a modest decrease in per capita energy use through “energy conservation”. From 2010 to 2100, the United States will need in total about 2,000 billion BOE of energy. At $100 per BOE, Americans would spend about $200 trillion on energy over the next nine decades.
The world’s energy needs during the remainder of this century are likely to climb even more rapidly than those of the United States as the world’s developing nations seek economic prosperity and political stability. Today, with only about five billion modern energy consumers, the world uses about 81 billion BOE per year—at roughly the same average per capita energy use as in the United States in 1900. As in the United States, about 85 percent of the world’s energy comes from non-sustainable easy energy sources. To project the world’s energy needs in 2100, 90 percent of today’s average per capita energy use in Japan, Western Europe, and South Korea was used as the basis for the projection. Per capita energy use in these industrial nations—about one-half of that in the United States—represents an energy-frugal standard of living that still enables widespread prosperity and political stability. In 2100, with about 10 billion energy consumers in economically-prosperous and politically-stable countries, the world will need about 280 billion BOE annually. This constitutes an increase from today’s energy consumption by a factor of about 3.5X. With these assumptions, between 2010 and 2100, the world will need about 17,000 billion BOE of energy and, at $100 per BOE, would spend roughly $1,700 trillion on energy.
With such a dramatic increase in world energy demand, a reasonable question is how much easy energy resources are left to use? Using the World Energy Council’s 2007 estimates, current world proved reserves of all oil, coal, and natural gas total about 6,000 billion BOE. Based on the optimistic estimates of some experts, a further 6,000 billion BOE of easy energy might be obtained through additional exploration and recovery improvements. For example, if nearly all shale oil in the United States were to be recovered, this could add upwards of 2,000 billion BOE. At best, one may conclude that there might be about 12,000 billion BOE of easy energy left to recover. A less optimistic planning value, due to growing legal and treaty constraints on exploration and recovery, would be 9,000 billion BOE.
Some argue that terrestrial sustainable energy sources can meet this challenge. In my white paper, this possibility was explored through a simple 2100 sustainable energy scenario focusing on meeting the United States’ 2100 needs. (Note that in 2100, the United States will need about 10 percent of the world’s total energy supplies.) In this scenario, these optimistic assumptions were made regarding nuclear and renewable energy expansion in the United States:
- Nuclear enriched uranium fission electrical power generation would be expanded from 101 GW today to 175 GW in 2100 (representing 10 percent of the world’s total 2100 nuclear capacity and consistent with a 120-year world supply of uranium from land resources without reprocessing or breeding).
- Hydroelectric generation capacity would be expanded from 78 GW to 108 GW (the estimated practical maximum in the US).
- Geothermal energy would be expanded from 3 GW to 150 GW (reflecting the Department of Energy’s goal for the western United States by 2050).
- 1.1 million 265-ton land and off-shore wind turbines would be built covering 390,000 square kilometers and stretching in a 8-kilometer wide band along 7,200 kilometers of coastline.
- 153,000 square kilometers of ground solar photovoltaic systems would be built in the southwestern desert states (with 100 percent land use).
- 1.3 billion dry tons of land biomass (based on 2005 Departments of Energy and Agriculture projections) would be collected annually from all cropland and accessible forestland and converted to biofuels and oil substitutes.
Nuclear, hydroelectric, geothermal, and a modest percentage of wind-generated electrical power are assumed to provide dispatchable electrical power generation to replace coal- and natural gas-fired generators. (Dispatchable generation capacity is what utilities require to prevent brownouts and blackouts while ensuring that customer needs can be met anytime.) Because of the variability of the wind and ground insolation, most wind-generated electricity and all ground solar electricity is assumed to be used to produce hydrogen and hydrogen-based synfuels. All biomass is assumed to be converted to fuels and other oil substitutes.
Three possible energy sources that could achieve sufficient generation capacity to close the 2100 shortfall are methane hydrates, advanced nuclear energy, and SSP. The key planning consideration is: Which of these are now able to enter engineering development and be integrated into an actionable sustainable energy transition plan?
SSP will jump-start the next era of the space age
Successfully developing SSP and building the integrated spacefaring logistics infrastructure necessary to demonstrate SSP and prepare for serial production of the geostationary platforms can only be successfully undertaken by a true spacefaring nation. The United States is not there yet because, as the US National Space Policy emphasizes, we have not yet developed the “robust, effective, and efficient space capabilities” needed for America to effectively utilize space this century.
Planning and executing a rational US energy policy that undertakes the development of SSP will jump-start America on the path to acquiring the mastery of industrial space operations we need to become a true spacefaring nation. This path will follow our nation’s hard-earned success, as seafarers and aviators, of building a world-leading maritime industry in the 18th and 19th centuries and an aviation industry in the 20th century. With this new spacefaring mastery, today’s dreams of expanded human and robotic exploration of space, of humans on Mars, of space colonies, of lunar settlements, and so on, will all move from the realm of wishful daydreams into an exciting future of actionable possibilities. The goal of nearly all American pro-space organizations is to make such a future a reality. Energetically supporting the incorporation of SSP into US energy planning and strongly advocating for the start of the development of SSP is how pro-space organizations can now take action to make their vision part of America’s broad-based spacefaring future. This is, indeed, a win-win opportunity that we cannot afford to miss.
http://www.thespacereview.com/article/1364/1
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timallard
Engineering
| Joined: | Thu Mar 5th, 2009 |
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Posted: Thu May 7th, 2009 12:04 am |
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Personally I think the estimated demand for energy is overstated due to the real lack of sustainable products and strategies being used globally, however that is, certain obvious energy fuel sources are being ignored that are totally adequate to supply all transportation fuels and local heating fuel needs globally without petroleum by using sewage wastewater from wastewater treatment plants around the world as the source of nutrition and growing medium.
An example is Phoenix, AZ, which produces 10-million gallons of secondary effluent per day, that's 83-million pounds of fertilizer you must get rid of by TOMORROW by having organisms extract the dissolved solids, then pressed for the oil to make biodiesel from on a daily basis. This also brings the water to nearly pure so it's treated and recycled back into the fresh water system.
This strategy reduces harmful global emissions by 60% over gas-ethanol if adopted globally to run our machines (MIT Tech Review, 2006). Not a panacea for global warming but a huge step in the right direction.
In space using wastewater has obvious advantages as a volume source of renewable fuel that grows directly with population.
Another point is that solar direct is not being seriously considered at all. Solar direct can supply the power for metalwork and ceramics internationally and these systems are rather simple. To ignore the power requirements of global metalwork and ceramics is about the pinnacle of ideological blindness.
A solar forge is a pile of ceramics under the focal area of the collectors and the heat from that is easy to channel into kilns and heat-treatment ovens, is this too easy and low-tech to actually work on and get to be a common method? Seems most of these strategies are overlooked due to their simplicity and the dumb idea that the sun doesn't always shine so why do it?
The earth-based reason to do it is money. I've started a new bicycle framebuilding business so am designing and builiding a solar system because of the reduced production costs. With a solar system I won't have hefty power bills and will use very little oxy-acetylene so I can produce a frame and make back the materials more easily and then have the bonus of a huge gain in profit until the market shifts and a majority of framebuilders are solar and can compete on price without losing their shirts.
The space-based reason is that a colony that has solar laser welding and brazing ability, and, ceramic kilns and a metal foundry with heat-treatment ovens can manufacture without much of an energy demand to non-renewable power systems. The utility and added safety to the colony of having this ability I don't think can be overlooked by any serious space scientist.
There may eventually be a need for these space-based power strategies where light is collected above the atmosphere, but until we've exhausted these simple biofuel extraction and solar direct things that can be done seems we're playing around.
Last edited on Thu May 7th, 2009 12:07 am by timallard
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